Well, the nail beds sounds like it could be from either infection or from vitamin deficiency or malnourishment. However, the pain doesn't make sense with that. Because of the gland swollen, I would say you should see your doctor. Pain in any part of the body that lasts maybe a day or two if it is not intense is not a worry as a rule, but more than two days ESPECIALLY if you don't' remember injuring that area is always a reason to get a doctor to check it out. Glands swollen are always a reason to be checked out, only because if it is something serious/semi-serious then it's best to catch it right away.
I would say to get checked out, and something that usually helps doctors is to have a small list of your diet for at least two weeks.
Yes you should be concered....see your doc